Efficient photorelease of carbon monoxide from a luminescent tricarbonyl rhenium(I) complex incorporating pyridyl-1,2,4-triazole and phosphine ligands

Dalton Trans. 2021 Feb 2;50(4):1313-1323. doi: 10.1039/d0dt03577g.

Abstract

Precise control over the production of carbon monoxide (CO) is essential to exploit the therapeutic potential of this molecule. The development of photoactive CO-releasing molecules (PhotoCORMs) is therefore a promising route for future clinical applications. Herein, a tricarbonyl-rhenium(i) complex (1-TPP), which incorporates a phosphine moiety as ancilliary ligand for boosting the photochemical reactivity, and a pyridyltriazole bidentate ligand with appended 2-phenylbenzoxazole moiety for the purpose of photoluminescence, was synthesized and characterized from a chemical and crystallographic point of view. Upon irradiation in the near-UV range, complex 1-TPP underwent fast photoreaction, which was monitored through changes of the UV-vis absorption and phosphorescence spectra. The photoproducts (i.e. the dicarbonyl solvento complex 2 and one CO molecule) were identified using FTIR, 1H NMR and HRMS. The results were interpreted on the basis of DFT/TD-DFT calculations. The effective photochemical release of CO associated with clear optical variations (the emitted light passed from green to orange-red) could make 1-TPP the prototype of new photochemically-active agents, potentially useful for integration in photoCORM materials.

MeSH terms

  • Carbon Monoxide / chemistry*
  • Coordination Complexes / chemical synthesis
  • Coordination Complexes / chemistry*
  • Density Functional Theory
  • Ligands
  • Luminescent Agents / chemical synthesis
  • Luminescent Agents / chemistry*
  • Models, Molecular
  • Molecular Structure
  • Phosphines / chemistry*
  • Photochemical Processes
  • Rhenium / chemistry*
  • Triazoles / chemistry*

Substances

  • Coordination Complexes
  • Ligands
  • Luminescent Agents
  • Phosphines
  • Triazoles
  • 1,2,4-triazole
  • Rhenium
  • Carbon Monoxide
  • phosphine